The foraging movements of bumblebees on vertical “inflorescences”: An experimental analysis

Summary

The bumblebees,Bombus edwardsii, move upward while visiting consecutive flowers on artificial “inflorescences”. This response is unrelated to the vertical patterning of rewards in the flowers of inflorescences. However, when rewards are greatest in the bottommost flowers the bees learn to start lower and leave before reaching the topmost (empty) flowers. Conversely, when rewards are greatest in the topmost flowers they tend to start in the middle of the inflorescence and depart from the top. When rewards are equal in all flowers bees start near the bottom and depart near the top of inflorescences. These behavioral patterns tend to maximize the number of visits to rewarding flowers while minimizing visits to non-rewarding flowers, thereby enhancing foraging returns.